How To Spell overtraining?

Correct spelling: overtraining

Google Ngram Viewer results for overtraining:

This graph shows how "overtraining" have occurred between 1800 and 2008 in a corpus of English books.

What are the usage examples for overtraining?

  1. Over- work in the shop or factory, overtraining in the gymnasium or on the athletic field, both fall first and heaviest upon the heart. – A Handbook of Health by Woods Hutchinson
  2. He also gives full directions for training for condition without danger of going stale from overtraining – Taxidermy by Leon Luther Pray
  3. It is rather my intention mildly to criticise some affectations and pretenses which I believe have grown out of overtraining among fishermen, or have resulted from too much elaboration of method and refinement of theory. – Fishing and Shooting Sketches by Grover Cleveland